The Hippocratic Oath
In the practice of medicine one basic principle stands out: What you eat has a major influence on your health. That principle is so simple and so logical that it is surprising the medical profession has had such a difficult time grasping it. The average doctor, despite having taken the Hippocratic oath, rejects the famous words proclaimed by Hippocrates: "Let your food be your medicine and let your medicine be your food." Had these doctors only met my late Uncle Ruben, who, well into his nineties, was still able to walk a brisk five miles every morning, they would have understood why he believed that "health comes from the farm, not the pharmacy."
A theme that keeps recurring in nutritional medicine is that degenerative diseases are caused, at least in part, by our modern diet, which contains too much sugar, fat, salt, refined flour, caffeine, alcohol, processed foods, and food additives. I routinely advise my patients, regardless of their specific medical problems, to try to clean up" their diet; that is, reduce their consumption of these junk foods" and to increase their intake of whole grains, fruits, vegetables, nuts and seeds, beans, and other unprocessed foods. The majority of people who follow that advice find that their health improves in some way. Many individuals report an increase in energy, less depression and anxiety, fewer headaches, better bowel and bladder function, and less fluid retention. They often sleep better, their joints do not hurt as much, and they are more alert and productive. Laboratory reports, such as serum cholesterol, triglycerides, liver enzymes, and uric acid also improve in many cases.
Specific medical conditions may also be relieved as a result of these general dietary changes. Patients with asthma, irritable bowel syndrome, peptic ulcer, gallbladder attacks, acne, psoriasis, high blood pressure, diabetes, angina, or other problems frequently find that their symptoms are better when they eat a healthier diet. Part of the appeal of improving your diet is that, even if it does not help, it rarely causes harm.
Diet and Bone Health
Considering that bone is living tissue, just like the rest of the body, it is likely that what you put in your mouth will determine in part how strong your bones will be. Many people believe that, aside from its calcium content, diet has little to do with osteoporosis. However, that assumption ignores the fact that bone tissue has diverse nutritional needs and engages in complex interactions with the rest of the body. It is improbable that our modem-day diet could be sparing our bones while damaging the rest of our body. Although it is impossible to determine the precise effect of diet on bone health, there is at least circumstantial evidence that the typical American diet promotes the development of osteoporosis.
There are three reasons that our modem diet might not be good for our bones. First, many of us ingest too much sugar, caffeine, salt, and alcohol. Consumption of each of these substances is reportedly associated with an increased risk of osteoporosis. Second, because of the way our food is grown and refined, today's diet probably contains much lower quantities of various vitamins and minerals than it used to. As you will learn later, some of these vitamins and minerals play a key role in maintaining healthy bones. Third, some of the processing techniques used by the food industry cause chemical changes in our food that may adversely affect the health of the tissues in our bodies, including bone. The possible influences of diet on bone health are reviewed next.
Sugar
In the early part of the nineteenth century, sugar was considered a condiment, rather than a major component of the diet. Back then, the average per capita intake of sugar was only about 10 to 12 pounds per year. Today, according to some statistics, the average American ingests approximately 139 pounds of refined sugar each year. That enormous quantity translates to about 41 teaspoons of sugar per day, or 19% of all of the calories we consume. Since refined sugar contains virtually no vitamins or minerals at all, it dilutes our nutrient intake, resulting in an across-the-board 19% reduction in all vitamins and minerals in our diet. Thus, because of our high intake of sugar we are getting less magnesium, folic acid, vitamin B6, zinc, copper, manganese, and other nutrients that play a role in maintaining healthy bones.
Ingesting sugar may also deplete our bodies of calcium. In one study, administering 100 grams (about 25 teaspoons) of sugar (sucrose) to healthy volunteers caused a significant increase in the urinary excretion of calcium. When the same amount of sugar was given to people with a history of calcium oxalate kidney stones or to their relatives, the increase in calcium excretion was even greater.) Since 99% of the total-body calcium is in our bones, this increase in calcium excretion most likely reflects a leaching of calcium from bone. This study suggests that a high-sugar diet may reduce the calcium content of bone, and that people with kidney stones or their relatives are especially susceptible to the adverse effects of sugar. Thus, the extent to which dietary sugar affects calcium metabolism is in part genetically determined, just as there is a hereditary component to osteoporosis risk. It is interesting to note that individuals with a history of kidney stones are at increased risk for developing osteoporosis.2 Researchers have also suggested that consumption of refined sugar is one of the factors that promotes kidney stones. Perhaps what people with kidney stones and osteoporosis have in common is an increased sensitivity to refined sugar.
Ingestion of large amounts of sugar has another effect on the body that may promote osteoporosis. Dr. John Yudkin, a British physician, has been studying the effects of dietary sugar for more than thirty years. Yudkin found that ingesting large amounts of sucrose by healthy volunteers causes a significant increase in the fasting serum cortisol level. Cortisol is the primary corticosteroid l (cortisonelike hormone) secreted by the adrenal gland. Although corticosteroids have important biological functions, an excess of these hormones can cause osteoporosis. Indeed, doctors are reluctant to prescribe corticosteroids precisely because they can cause severe bone loss. Yudkin's work demonstrated that eating too much sugar is in a way analogous to taking a small amount of cortisone, which could cause your bones to become thinner. This possibility is supported by a study on hamsters, in which feeding a diet containing 56% sucrose caused osteoporosis, despite adequate intake of calcium.3
Refined Grains and Flour
Another significant dietary change occurring during the past century is an increase in the consumption of refined grains, such as white bread instead of whole wheat bread, and white rice instead of brown rice. During the refining of grains and flour the nutrient-rich germ and bran portions are removed, resulting in a significant loss of vitamins and minerals. For example, when whole wheat is refined to white flour the following percentages of selected vitamins and minerals are lost: vitamin B6 (72%), folic acid (67%), calcium (60%), magnesium (85%), manganese (86%), copper (68%), zinc (78%).4 Since grains make up about 30% of the average diet, consumption of refined grains would have a substantial impact on the total daily intake of micronutrients (vitamins and minerals). Because nearly 50% of the typical American diet is composed of nutrient-depleted sugar and refined grains, the intake of many important micronutrients is probably much lower than it was during the previous century
Caffeine
Caffeine is found in coffee, tea, cola beverages, and certain pain medications. Substances similar to caffeine are also present in chocolate. Caffeine has certain pharmacologic (druglike) effects in the human body and is known primarily as a stimulant of the central nervous system. Tens of millions of people depend on caffeine to help them wake up in the morning and to stay alert during the day. Athletes sometimes use caffeine to enhance their performance.
Although the dangers of caffeine have long been a topic of debate, it is well known that caffeine is an addictive substance. Withdrawal from caffeine after prolonged use usually results in severe headaches, which can last several days. It is also well known that excessive caffeine use is a cause of anxiety and insomnia.
Nutrition-oriented practitioners and some conventional doctors believe that caffeine can also cause certain other problems in susceptible individuals. Problems attributed wholly or in part to caffeine include fibrocystic breast disease, cardiac arrhythmias (heart rhythm disturbances), diarrhea, constipation, abdominal pain, elevated serum cholesterol or blood sugar, high blood pressure, and chronic migraines or other headaches. There is evidence that caffeine may also promote heart disease and cancer, although the studies in this area are conflicting.
It should not be surprising that a substance that appears to cause problems in so many different systems of the body would also adversely affect bone tissue. Most of the evidence is circumstantial, but studies do suggest that caffeine ingestion may contribute to bone loss. In one study, thirty-one women ingested a cup of decaffeinated coffee on three different occasions. In two of the cups, caffeine was added at concentrations of 3 mg/kg and 6 mg/kg of body weight, respectively. The excretion of calcium in the urine during the next three hours was significantly greater after caffeine ingestion than after decaffeinated coffee. The increases in calcium excretion were 50% and 69%, respectively, after low and high doses of caffeine.5 These results demonstrate that ingestion of caffeine causes excess calcium loss from the body in the short term.
Another study suggests that this effect of caffeine is not just limited to the short term. Calcium balance, a measure of the amount of calcium retained in the body, was assessed in 168 women between the ages of 35 and 45. The results showed that calcium balance decreased with increasing dietary intake of caffeine. In other words, women who habitually ingested a great deal of caffeine retained less calcium than did those who used little caffeine. Women who consumed 50% more caffeine than average had an estimated; reduction in calcium balance of 6 mg/day.6 Although 6 mg/day might seem like a small amount, a loss of that much calcium every day for years would add up to a significant degree of bone loss.
The potential consequences of caffeine ingestion on bone health was assessed in a study of 84,484 women the ages of 34 and 59. In 1980, each of the women completed a questionnaire pertaining to their intake of various foods and beverages. During the ensuing six years, there was a positive association between caffeine intake and the risk of sustaining a hip fracture. That is, the risk of a hip fracture increased with increasing levels of caffeine intake. Women who consumed the most caffeine (above the 80th percentile) had nearly three times as many hip fractures as women who consumed the least caffeine (below the 20th percentile).7 One possible confounding factor in this study is that women who use caffeine also tend to smoke cigarettes, which are known to contribute to the risk of osteoporosis. It is possible that some of the risk attributed to caffeine intake was actually due to tobacco. However, the weight of evidence suggests that anyone interested in maintaining healthy bones should avoid excessive caffeine intake.
Alcohol
Consumption of excessive amounts of alcohol is a known risk factor for osteoporosis. In a study of ninety-six male chronic alcoholics): ages 24 to 62, 47% had osteoporosis. Among those under the age of 40, 31% had osteoporosis.8 Although a similar study has not been done on women, it is likely that drinking too much alcohol would also promote osteoporosis in women. The effect of moderate alcohol consumption on bone health is not known.
Protein, Phosphorus, and Sodium
The American diet tends to contain too much, rather than too little protein. Studies have shown that excessive dietary protein may promote bone loss. With increasing protein intake, the urinary excretion of calcium also rises, because calcium is mobilized to buffer the acidic breakdown products of protein. In addition, the amino acid methionine is converted to a substance called homocysteine, which is also apparently capable of causing bone loss.
Animal studies have shown that excessive intake of phosphorus can cause osteoporosis, as well. The effect of dietary protein on osteoporosis might be explained in part by the phosphorus content of many high-protein foods because phosphorus does appear to have an adverse effect on bone health. High-phosphorus beverages such as colas (which also contain a lot of sugar and caffeine) are among the worst foods imaginable for someone trying to prevent osteoporosis.
Several studies have shown that individuals who consume a vegetarian diet have stronger bones later in life than those who eat animal flesh.9,10 However, other studies have failed to find a difference in bone mass between vegetarians and meat eaters.
A substantial minority of human beings also appears to be Susceptible to the effects of high-sodium intake. When these individuals ingest moderate amounts of salt, their urinary excretion of calcium increases markedly." In people with this sodium-dependent hypercalciuria, ingestion of too much salt probably increases the risk of both kidney stones and osteoporosis. In today's fast paced society, great emphasis is placed on readily available, easily prepared food, which can be stored on the shelf for prolonged periods of time. The food technology industry has developed many ways to achieve these goals. Unfortunately, the nutritional quality of processed, adulterated food is far inferior to that of fresh, perishable foods. Modern food is bleached, radiated, extracted with organic solvents, subjected to enormous temperatures and extremes of acidity or alkalinity, and contaminated with thousands of chemicals designed to preserve, texturize, color, or otherwise modify the food so that it will look, feel, and taste like the real thing.
Hundreds of articles have been written about how these harsh processing techniques can affect the nutritional value of food. One I example is the possibility that food processing can promote lysine deficiency. Lysine is one of the eight essential amino acids from which protein molecules are synthesized in the body. Studies have shown that when proteins are subjected to alkali treatment (as in the production of isolated soy protein or textured vegetable protein), a substantial amount of the lysine is destroyed.l2 Exposure of lysine to temperatures of 250¡C for one hour also caused significant losses of lysine.l3 Heating proteins even at moderate temperatures in the presence of sugars such as lactose, glucose, or sucrose can also destroy significant amounts of lysine.14 Thus, in the baking of pies, cookies, breads, and other grain products, where flour and sugar are heated together, substantial amounts of lysine may be lost.
You might assume that, with all of the protein in the American diet, it would be difficult to develop a deficiency of an amino acid. The problem is, however, that amino acid imbalance can be just as damaging as amino acid deficiency. Animal studies have shown that the ratios of essential amino acids in the diet are as important as the absolute amount of each. If a single amino acid, such as lysine, is being systematically destroyed by food processing, then ingesting more of all of the amino acids will not correct a relative lack of lysine.
It is therefore possible that millions of Americans are marginally deficient in Iysine, even if their diet is high in protein. The modern epidemic of herpes simplex infections is certainly consistent with that possibility. Lysine is known to inhibit the growth of herpes viruses and oral supplementation with Iysine has been shown to prevent recurrences of herpes simplex outbreaks in susceptible individuals.15, l6 Since the doses of lysine that were effective against herpes infections (312 to 3,000 mg/day) are similar to the amounts obtainable in the diet, it is possible that dietary lysine deficiency is a factor in the increased incidence of herpes simplex infections.
It is also possible that lysine deficiency contributes to the development of osteoporosis. Individuals with a rare genetic condition known as lysinuric protein intolerance develop osteoporosis during childhood. In lysinuric protein intolerance, a defect in the kidneys causes large amounts of lysine to be lost in the urine. Scientists have suggested that lysine deficiency is the cause of osteoporosis in individuals with this disorder.17 Although the typical American diet would not result in Iysine deficiency that severe, it is possible that prolonged, subtle lysine deficiency caused by harsh food processing techniques could have an adverse effect on bones.
Soil Factors
The reduction in vitamin and mineral intake resulting from refining of foods can be made even worse by farming techniques that deplete the soil of essential minerals. Traditional methods of farming include using manure and compost to increase the trace mineral content of the soil. In modern times, however, with the emphasis on producing higher crop yields per acre, farmers use large amounts of inorganic fertilizers, which are often deficient in important trace minerals and which may disturb soil mineral balance. For example, the use of ammonia as a fertilizer causes essential minerals such as magnesium' manganese, zinc, and copper to be leached from the soil.18 Repeated application of inorganic fertilizers, which are low in essential trace minerals, can further reduce the soil concentration of these trace minerals. Many scientists and nutritionists are unaware of the effect the depleted soil can have on the mineral content of edible plants i Indeed, nutrition textbooks often contend that mineral-deficient soil will reduce crop yield, but will not adversely affect the nutritional quality of crops that do grow. However, the facts indicate otherwise. The presence of a "goiter belt" in the midwestern United States attests to the fact that foods grown on iodine-deficient soil can cause iodine deficiency. The relationship between mineral concentrations in soil and food is also underscored by the epidemics of selenium deficiency that have occurred in cattle grazing in low selenium areas of the country. As another example, dairy cattle an horses are sometimes stricken by a condition known as grass staggers, characterized by unsteady gait and twitching and spasm of the muscles. This disorder can be cured either by supplementing the diet with magnesium or by adding magnesium to the soil.19 It appears that overuse of nitrates, phosphates, and potassium salts as fertilizers depletes the soil of magnesium and causes a deficiency of this mineral in grazing animals. In the Florida Everglades the soil is low in copper. Domestic animals grazing in this area develop copper deficiency which makes them unusually susceptible to sus~ taining bone fractures. But, when copper is added to their diet fractures no longer occur.20 In another study, the manganese content of turnips was directly related to the manganese content of -the soil. Addition of calcium carbonate to the soil (a common practice by modern farmers) decreased the accumulation of manganese by turnips.
Conclusion
These studies indicate that modern farming practices deplete the soil of essential minerals, resulting in lower levels of these minerals in our food. The vitamin and mineral content of our diet is further reduced by overconsumption of nutrient-depleted foods, such as sugar and white flour. The net result is that the food we consume today contains far less of many vitamins and minerals than it did in the past. One of the major theses of this book is that chronic, low level deficiencies of a wide range of micronutrients may increase the risk of developing osteoporosis.
In summary, many factors related to the modern American diet may promote not only osteoporosis, but other chronic diseases, as well. A health-promoting diet is one that emphasizes fresh, unprocessed foods, such as whole grains, fruits and vegetables, nuts and seeds, and legumes Animal foods, dairy products, and salt should be used in moderation, and sweets, caffeine, refined flours, and chemical food additives should be avoided as much as possible. While some studies suggest that moderate alcohol intake improves health, others have shown that even small amounts of alcohol are not good for you. Certainly, excessive alcohol intake can cause many different problems, including osteoporosis. The human body is remarkably resilient and is capable of withstanding numerous stresses, but it is also true that the more closely you follow the principles of good eating, the healthier you will be.
Notes
1. Lemann, J., Jr., W. F. Piering, and E. J. Lennon. 1969. Possible role of carbohydrate-induced calciuria in calcium oxalate kidney-stone formation. No Engl J Med 280:232-237.
2. Lawoyin, S., et al. 1979. Bone mineral content in patients with calcium urolithiasis. Metabolism 28:1250-1254.
3. Yudkin, J., Dr. 1973. Sweet and dangerous. New York: Bantam Books, 112. Saffar, J. L, et al. 1981. Osteoporotic effect of a high-carbohydrate diet (Keyes 2000) in golden hamsters. Arch Oral Biol 26:393-397.
4. Schroeder, H. A. 1971. Losses of vitamins and trace minerals resulting from processing and preservation of foods. Am J Clin Nutr 24: 562-573.
5. Hollingbery, P. W., E. A. Bergman, and L K Massey. 1985. Effect of dietary caffeine and aspirin on urinary calcium and hydroxyproline excretion in pre and postmenopausal women. Fed Proc 44:1149.
6. Heaney, R P., and R R Recker. 1982. Effects of nitrogen, phosphorus, and caffeine on calcium balance in women. J Lab Clin Med 99:46-55.
7. Hernandez-Avila, M., et al. 1991. Caffeine, moderate alcohol intake, and risk of fractures of the hip and forearm in middle-aged women. Am J Clin Nutr 54: 157-163.
8. Spencer' H., et al. 1985. Alcohol-osteoporosis. Am J Clin Nutr 41:847.
9. Marsh, A. G., et al. 1980. Cortical bone density of adult lacto-ovo-vegetarian an omnivorous women. J Am Diet Assoc 76:148-151.
10. Marsh, A. G., et al. 1983. Bone mineral mass in adult lacto-ovo-vegetarian an omnivorous males. Am J Clin Nutr 37:453-456.
11. Silver,J., et al. 1983. Sodium-dependent idiopathic hypercalciuria in renal-stor formers. Lancet 2:484-486.
12. de Groot, A P., and P. Slump. 1%9. Effects of severe alkali treatment of prose on amino acid composition and nutritive value. J Nutr 98:45-56.
13. Breitbart, D. J., and W. W. Nawar. 1979. Thermal decomposition of Iysine. J Agric Food Chem 27:511-514.
14. Hurrell, R. F., and K J. Carpenter. 1977. Mechanisms of heat damage in prose
8. The role of sucrose in the susceptibility of protein foods to heat damage Br J Nutr 38:285-297.
15. Griffith, R S., A. L Norins, and C. Kagan. 1978. A multicentered study of Iysine therapy in herpes simplex infection. Dermatologica 156:257-267.
16. Griffith, R S., et al. 1987. Success of L-lysine therapy in frequently recurrence herpes simplex infection. Dermatologica 175:183-190.
17. Carpenter, T. O., et al. 1985. Lysinuric protein intolerance presenting as child hood osteoporosis. N Engl J Med 312:290-294.
18. Hall, R. H. 1981. The agri-business view of soil and life. J Holistic Med 3:15 166.
19. Ebeling, W. 1981. The relation of soil quality to the nutritional value of plant crops. J Appl Nutr 33(1):19-34.
20. Rose, E. F. 1968. The effects of soil and diet on disease. Cancer Res 28:2390 2392.
21. Hopkins, H. T., E. H. Stevenson, and P. L Harris. 1966. Soil factors and food composition. Am J Clin Nutr 18:390-395.
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